French published patent specification describes a laser device for guiding a missile to a target, in which the missile is launched towards a target and including flight controller means for modifying the direction of its movement. This prior device is of the type comprising:
a guidance station including:
an automatic missile pointing system comprising: PA1 means for measuring the distance of the missile, said means comprising: PA1 means for measuring the distance of the target; PA1 an aiming sight which is pointable towards the target; PA1 angle measuring means for delivering information on the angular position of the missile, said position being determined by the said pointing means, the angular position information being relative to the direction in which the sight is pointed; PA1 a computer connected to the missile telemeter circuit, to the said means for measuring the distance to the target, and to the said angle measuring means, said computer being capable firstly of determining a trajectory for the missile towards the target on the basis of the information on the distance to the missile, on the distance to the target, and on the angular position of the missile, and also capable of generating piloting signals suitable for controlling the said flight controller means to guide the missile on said trajectory; and PA1 a modulator control circuit connected to the computer to modulate the said laser pulses at the frequency F.sub.1 with the said piloting signals; PA1 a reflector fixed to the aiming sight to direct the second beam towards the target; and PA1 a pulse receiver system for receiving pulses from the second beam as reflected by the target, said system being fixed to the aiming sight and being connected to the computer, said system being capable of measuring the time interval between transmitting a laser pulse of frequency F.sub.2 and its return to the guidance station after reflection by the target, said time interval being representative of the distance to the target.
a laser beam generator, including a transmitter for transmitting laser radiation at a frequency F.sub.1, said generator being provided with beam pointing means for pointing the beam towards a target which returns a portion of the beam energy in the opposite direction; PA2 an error measuring system fitted with an electro-optical receiver disposed to receive the said returned portion of energy, the receiver being suitable for delivering an error measuring signal in response thereto representative of the angle of error between the position of the missile and the axis of the beam; and PA2 a servo-control circuit suitable for controlling the beam pointing means to reduce the angle of error; PA2 a modulator constituting a part of the said generator, said modulator being suitable for receiving the laser radiation delivered by the transmitter and for delivering laser pulses at the frequency F.sub.1 in response thereto; and PA2 a missile telemeter circuit, connected to the modulator and to the output of the electro-optical receiver to measure the time interval between the tranmission of a laser pulse at the frequency F.sub.1 and its return to the receiver after being returned from the missile, said time interval being representative of the missile;
and a laser beam receiver circuit disposed on board the missile and connected to the said flight controller means, said circuit being capable of receiving the said modulated laser pulses at frequency F.sub.l and of delivering the said piloting signals in response thereto;
In this laser device, the means for measuring the distance to the target comprises a telemeter fixed to the aiming sight. This telemeter may be a laser telemeter, for example, in which case, the device includes two laser transmitters:
a first laser transmitter serving, together with a receiver and a telemeter circuit, for telemtery of the missile and for automatic missile pointing, said first laser transmitter being capable also of serving to transmit piloting signals to the missile; and
a second laser transmitter for target telemetry.
The aim of the present invention is to improve the device described in the above-mentioned published French patent specification No. 2 525 339 so that all the above-mentioned functions can be performed by a single laser transmitter.